Method For Monitoring Therapy Research Articles

Osmotherapy: Use Among Neurointensivists

Cerebral edema and raised intracranial pressure are common problems in neurological intensive care. Osmotherapy, typically using mannitol or hypertonic saline (HTS), has become one of the first-line interventions. However, the literature on the use of these agents is heterogeneous and lacking in class I studies. The authors hypothesized that clinical practice would reflect this heterogeneity with respect to choice of agent, dosing strategy, and methods for monitoring therapy. An on-line survey was administered by e-mail to members of the Neurocritical Care Society. Multiple-choice questions regarding use of mannitol and HTS were employed to gain insight into clinician practices. A total of 295 responses were received, 79.7% of which were from physicians. The majority (89.9%) reported using osmotherapy as needed for intracranial hypertension, though a minority reported initiating treatment prophylactically. Practitioners were fairly evenly split between those who preferred HTS (54.9%) and those who preferred mannitol (45.1%), with some respondents reserving HTS for patients with refractory intracranial hypertension. Respondents who preferred HTS were more likely to endorse prophylactic administration. Preferred dosing regimens for both agents varied considerably, as did monitoring parameters. Treatment of cerebral edema using osmotically active substances varies considerably between practitioners. This variation could hamper efforts to design and implement multicenter trials in neurocritical care.

Translating Hemoglobin A1c into Average Blood Glucose: Implications for Clinical Chemistry

Measurement of hemoglobin A1c (Hb A1c)1 is a fundamental component of the management of patients with diabetes mellitus. Hb A1c measurement provides an indication of chronic exposure to glucose and is extensively used for both monitoring long-term glycemic status and evaluating whether an individual patient has attained adequate metabolic control. The patient’s Hb A1c value is used by clinicians to determine whether glucose-lowering therapy is adequate. A recent report (1) establishes a mathematical relationship between Hb A1c and the average glucose (AG) concentration in blood. The findings presented are likely to have considerable impact on the way Hb A1c is reported by clinical laboratories and used by healthcare providers (and patients). The importance and potential consequences of the study are the focus of this Perspective. The efficacy of therapy to lower blood glucose in patients with diabetes mellitus is assessed by 2 complementary methods, glucose measurement, which is performed by patients, and Hb A1c measurement. Patients perform self-monitoring of blood glucose (SMBG) by using hand-held meters to measure their own blood glucose concentrations. It is recommended that patients on insulin perform SMBG 4 times a day. The dose of the insulin injection is determined by the glucose value. Many modern meters store the results of all the glucose measurements, which can be downloaded and accessed by the physician during the patient’s visit. The second method for monitoring therapy to lower blood glucose is measurement of glycohemoglobin, most commonly performed by assaying Hb A1c. Glycohemoglobin is formed by the attachment of glucose to hemoglobin by a nonenzymatic process, termed glycation. The erythrocyte membrane is permeable to glucose, which enters the cell, where it binds to hemoglobin. The unstable product, termed an aldimine, undergoes an Amadori rearrangement to form a stable …

Cellular pharmacokinetics of daunorubicin: uptake by leukaemic cells in vivo and fate.

In 6 patients with acute myeloblastic leukaemia, daunorubicin was assayed in leukaemic cells from peripheral blood or bone marrow. The cells were separated from red blood cells and granulocytes by centrifugation on a Ficoll-Isopac gradient. The assay was performed by high performance liquid chromatography. Daunorubicin concentrations in peripheral leukaemic cells, 2 hours after the end of the infusion, were much higher than in plasma, the cell/plasma concentration ratio reaching about 350 and rising to almost 700 at 24 h. At that time, drug concentrations were even higher in the bone marrow leukaemic cells. The value of the assay of daunorubicin in cells as method for monitoring therapy is discussed.

Heparin: A drug of varying composition and effectiveness

In the past few years concerns have been expressed by clinical investigators regarding the variable and unpredictable risk of both hemorrhage and thrombosis in patients receiving heparin. Recent observations tend to indicate that a number of elements may contribute to variability in response to heparin. Possible factors which may be responsible include differences in chemical composition and in methods of assay, variable absorption, different types and degrees of alteration in coagulation mechanism of patients, and inaccuracies or inadequacies in methods for monitoring therapy.